1. Field of the Invention
The present invention relates to a process for aiding the maintenance of a complex system, as well as a device for implementing this process.
2. Description of the Related Art
Within the context of the present invention, the expression complex system is understood to mean a system comprising a plurality of components, especially electronic, mechanical and hydraulic components, exhibiting numerous interconnections. Complex systems of this type exist in a great variety of fields of activity, such as for example in industry, in the automobile sector or in aviation.
For the maintenance of a complex system of this kind, in particular an aircraft such as a helicopter, in the simplest cases a maintenance plan is formed which catalogs the potential failures of said complex system and describes the refurbishment procedures suitable for the situation encountered. This known approach has a major drawback due to the unforeseen and unforeseeable nature of the moment of the failure so that it is often completely inadvisable, or even impossible, to implement it, for safety reasons.
By way of illustration, with regard, for example, to the lubricating of the engine of a vehicle, this known approach presupposes that the oil is neither changed nor checked, but that the consequences of the loss of lubrication are awaited in order to carry out a maintenance action, which is of course absurd.
To remedy this drawback, another known maintenance procedure advocates the use of a concept of preventive maintenance, which in its simplest version consists in periodically exchanging or overhauling parts or elements of the complex system. In the aforesaid exemplary illustration, this approach consists in carrying out drainage at regular time intervals, for example every three months (a period which is presumed to be sufficient in order for the oil for example of an optimally running automobile to be degraded). The drawback of this maintenance procedure relates to the operational constraints (availability, cost) related thereto, since the maintenance is performed prior to failure, usually on parts which are still serviceable.
It will be noted that another known procedure advocates that the state of the parts be monitored directly, this entailing drawbacks due to the quality of the observation criteria, to their representativity, to the constraint imposed on the user of the complex system and to the risks of errors.
In practice, the constructor of the complex system or the maintenance operator seeks, among the various possible maintenance options, the best compromise between the risk of an unforeseen failure, and one which is therefore penalizing in respect of safety or availability, and prior maintenance, which is therefore expensive and constraining.
However, this compromise generally entails a maintenance deadline which is very much ahead of the optimal deadline and, usually, the changed parts are still in a satisfactory state of serviceability when they are replaced.
Accordingly, for parts such as the settings for the blades of a helicopter, for example, for which any maintenance error is proscribed for obvious safety reasons, the margins regarding the timescales for changing parts are considerable and/or the maintenance regarding the monitoring of the state of the parts is very unwieldy.